A file system in a computer generally is part of the operating system that manages access to data in files stored on one or more storage devices. The file system provides an interface through which other applications can create and manage file system objects, write data to files and read data from files stored on the storage devices.
An operation that can be provided by a file system is copying a file. A file can be copied for various purposes. In some instances, a purpose of the copy of the file is to provide a backup copy, which is not intended to be modified, while the original file is subsequently modified. Another purpose is to provide a separately modifiable clone of the original file.
Another operation that can be provided by a file system is rearranging one or more files. For example, data in the file may be arranged in an order that is inefficient for accessing the data. Such rearrangement can be used, for example, if a portion of data in a file is no longer wanted, and a new file is created using only the desired data. As another example, a file can be split into two files. As another example, two files can be joined together.